Creating a Light Part

	This task explains what a light object (also called light part) is and how you should use it. The procedure for creating a light part is explained in this task, and in Creating a Part. For the rare situations when you have started the design process using heavy objects, and determine that they be replaced with light objects, you can replace them. See Replacing Heavy Parts with Light Parts below.
	You should build a part as a light object in order to save disk space and ensure faster loading of your documents. When you are adding a connector to a light part, you do not need to select geometry because light parts do not have the kind of geometry needed to add connectors.
		Three types of parts can be created as light objects. These are: Weld Straight routable part Bendable Explaining the Difference Between a Light and Heavy Part When you place a heavy part (refers to a parametric part that is not created as a light object) in your document, you end up creating a separate document for each unique reference. This is not the case when you place a resolved part. The placed part simply points to the catalog, and a unique document is not necessary. The light object approach applies the concept of a resolved part to a unique reference. When you build a part as a light object, you do not create the geometry of the part. Instead, you build the part, and designate it as a light object, as described the section Building Parts, and place it in a catalog. When you place the part in a document, this application will automatically create the visualization for it. You should also note that differing lengths of a placed light object do not result in the creation of a separate document for each placement. As an example, when you first place a 10-inch pipe in a document, a separate document is created for that part. However, when you place a 10-inch pipe again in the same document, a separate document is not created. All instances of a 10-inch pipe will refer to the first document that was created.
		The procedure for creating a light part is similar to that of creating a heavy part with one important difference. Since light parts do not have a graphic to begin with, you need to start by creating a type for the part. Click the `Build Part` button to display the `Create Part` dialog box. Click the `Display Class Browser` button next to the `Component Type` field. The Class Browser appears. The Class Browser allows you to select the type of part you want to create. Navigate to the type you want by clicking on the "plus" sign next to each directory, or by using the three navigation buttons at the bottom. You can also filter for certain types. For instance, you can enter "elbow" in the Filter field and select enter to see all elbow types. Click `OK` after making your selection. If you select a type in the class browser that can be created as a light part, then the `Create Part` dialog box will display the checkbox `Make light object` . The default is checked. If you do not want to create a part as a light object then uncheck this. Follow Step 5 onward in the task Creating a Part.
		Object Naming Rules for HVAC Ducts If you want to place heavy HVAC duct, you need to change the file that defines the object naming rules. (You do not need to make any change if you are placing 'light' parts.) If you are placing heavy parts then navigate to the directory `...intel_a\startup\EquipmentAndSystems\HVAC\DataDictionary`. The default files are named `sch-CATHvaHVACXXXXDuct1.xml` where XXXX represents a shape like FlatOval. Rename this file so that the application does not recognize it - you can add a `SAVE` at the end, for instance. You need to use the corresponding file that has the `_HV` at the end of the file name. This file is in the same directory, and normally directly beneath the file for light parts. To use this file simply remove the `_HV`. As an example: Rename `sch-CATHvaHVACXXXXDuct1.xml` to `sch-CATHvaHVACFlatOvalDuct1_SAVE.xml` Remove the `_HV` from the file `sch-CATHvaHVACFlatOvalDuct1_HV.xml`
		Replacing Heavy Parts with Light Parts
		You need to modify the parts catalog before replacing parts.
	1.	Open the appropriate catalog in the Catalog Editor, and remove the heavy parts.
	2.	Add the light parts to the catalog. Make sure that the part numbers of the light part references are unique. NOTE: If any other part in the catalog has the same part number as the added light part references, you will not be able to replace the heavy parts.
		To replace heavy parts with light parts:
	1.	Select the parts in your design document that you want to replace. You can use any method to multi-select the parts. Click the `Resize/Respec Part` button , and the Resize/Respec dialog box displays.
	2.	Click the Replace button, and the Define Parts Options dialog box displays. You can see the heavy parts that you selected display under the From column. Select a heavy part from the From column, and the Options list becomes available.
	3.	For every heavy part listed under the From column, select a light part from the Options list. NOTE: Make sure you select only light parts from the Options list. You can see your selections display under the To column. Click OK when you have chosen an option for all of the heavy parts listed.
	If a light object, such as a light pipe, is connected at its extremities to another object, the Replace command maintains the connectivity. All instance attributes are maintained. The conversion process from heavy to light should not impact any design data that has been already defined on the heavy object.